Magnesium-Teflon compositions are used in a variety of tracer rounds. These dry mixtures require extremely high pressures to consolidate them into tracer cavities. Since such high consolidation pressures can deform projectiles, elaborate precautions are required to support them during loading of the tracer charge. Moreover, mixtures of magnesium and Teflon powder may not press uniformly and as a result, give erratic ignition and burn times. During temperature cycling and vibration testing, pressed magnesium-Teflon mix pulls away from the case wall and cracks causing burning down the sides and into the grain resulting in the grain being ejected before being completely burnt out in the tracer cavity. Magnesium-Teflon mixes give, however, white light and burn at a very high flame temperature.
Certain color producing tracer mixes use a dry mixture of strontium nitrate and magnesium powder which is pressed at extremely high pressures into the tracer cavity. Additives such as calcium resinate and oxamide lower the burning rate. These additives, while reducing the burn rate, considerably decrease the light and heat output of the magnesium-strontium nitrate mixture. This dry mixture also breaks up on temperature cycling and vibration tests and pulls away from the case wall resulting in erratic burning. Certain other tracer mixes use binders for better consolidation of the tracer mix. These hydrocarbon binders, however, tend to reduce the heat and light output of these tracer compositions.
Mixtures of magnesium and fluorine-containing polymers such as combinations of Teflon and Vitron A have been disclosed for use as solid propellants (see, for instance, U.S. Pat. Nos. 3,876,477 and 3,463,682) and other purposes as igniter strands (see U.S. Pat. No. 3,765,334). Other patents of interest include U.S. Pat. Nos. 3,135,201; 3,671,341; 3,732,132; 3,770,525; 3,872,192; 3,983,816 and 4,019,932.
All of the above cited patents are hereby incorporated by reference as evidencing a state of the art.